Now his rivals know that Chris Froome is not just a bully when his mates are around. On a day when Team Sky's train, for once, came careering off the track - in Peter Kennaugh's case, plunging 5m down a grassy bank - the Tour de France leader, friendless and encircled by sharks, survived bite after bite to still be pristine in yellow.
If the dazzling climb up to Ax 3 Domaines on Sunday morning said everything about Froome's talent, then a second, even more demanding schlep over four Category One climbs in the Pyrenees yesterday told his opponents all they needed to know about his spirit and guts.
As the talented Dan Martin became the first Irishman since his uncle Stephen Roche 21 years ago to win a Tour stage, Froome the battling fireman proved, if anything, even more impressive than Froome the twisting firestarter.
"One of the hardest days I've ever had on a bike," he said, after retaining his 1 min 25s lead over Alejandro Valverde.
On Sunday, Dave Brailsford, their team principal, had described Sky's collective effort as one of the greatest team performances in Tour history. When Froome burst clear over the final stretch, he reckoned it had been like watching the completion of a "nine-darter". Like Phil the Power on pedals, just perfect.
Yesterday, though, Sky were missing the target from the start of a quite exhilarating ninth stage and, by the end, with Vasil Kiryienka out of the race altogether after failing to beat the time limit, Kennaugh having suffered his tumble and, worst of all, Richie Porte dropping from second overall to 33rd after losing 17 minutes, it felt like they could not hit a double to save their lives.
Yet Froome was calm personified amid the calamities. While not about to deny what blows these had been, he shrugged and said: "This is bike racing. [Yesterday] showed us there is a lot more to it than going fast up a mountain finish."
The peloton wanted revenge. "There are wounded egos out there," warned David Millar at the start in Saint-Girons, after Sky's demolition job.
He was right. The attacks poured in from the start and Sky had, by the top of the first climb - the not overly ferocious Col de Portet-d'Aspet - all been dropped.
Froome looked momentarily fazed. He glanced across to see Kennaugh disappearing when Garmin's Ryder Hesjedal, trying to escape plummeting a steep, grassy bank, inadvertently nudged the young Olympic champion down there instead. Charming.
Breath was held. Was he all right? Kennaugh's arms appeared from the undergrowth and, Spiderman-style, he crawled back up the bank covered in blood. Another superhero impression saw him reach the peloton and try to help Porte. Alas, he had no more to give.
Then we really saw Froome's sangfroid. He was alone, except for Sky's director Nicolas Portal in the team car telling him not to worry, even though the vultures hovered and swooped. At least six times over the 1170km parcours, Froome had to leap up in the saddle to chase down the largely Movistar-inspired attacks. Four times in 2km on the final ascent of La Hourquette d'Ancizan, Nairo Quintana tried to nail him. Each time Froome hit back, instantly and unbreakably.
The victor, Martin, felt Froome's pursuers had let a weakened Sky off the hook by not launching even more concerted assaults. Yet Froome just shrugged: "They did go for me. It is not easy to follow Quintana. He's a light little Colombian who can fly up hills so to cover his attacks definitely wasn't easy. But I was ready for more attacks."
The ones he was happy to let go were Martin, 5km from the top of Ancizan and no danger in the general classification, and Astana's Jakob Fuglsang as the pair ended up engaging in track-style, cat-and-mouse foreplay before the Garmin man flew away to win the sprint.